I’m actually working on a language like this. I quite liked ReScript/ReasonML, but having to manually write binding to use TypeScript or JS code is a drag. I’m making a functional language that looks and feels like TS and lets you import TS directly. Mostly just stripping imperative statements, removing class declaration and adding pattern matching and better data constructors (never liked the discriminated unions). WASM as a target is a bit further off.